The present invention relates to a novel process for producing amino compounds, and particularly to a process for producing amino compounds by enantioselectively converting Cxe2x80x94H bonds at the allyl positions of alkenes or at the benzyl positions of aklylarenes, to the corresponding Cxe2x80x94N bonds.
The amination of Cxe2x80x94H bonds of organic compounds is one of the most useful techniques in synthetic chemistry, particularly because a number of compounds having amino groups exhibit physiological activities that make them important as medicinal or agricultural materials and their intermediates.
However, reactions applicable to the amination of Cxe2x80x94H bonds are actually very few. Only a small number of amination reactions have been proposed for the Cxe2x80x94H amination using complexes of metals with porphyrin, cyclic amines or bipyridine as catalysts. Another such reaction is the one proposed by the present inventors, in which the amination reaction of Cxe2x80x94H bonds proceeds under Kharash-Sosnovsky conditions using a copper catalyst (Japanese Patent Application Publication No. 140044/1998). However, these reactions are all directed to the preparation of simple amino compounds and none are for producing optically active aminocompounds. While some asymmetric syntheses have been proposed for preparing optically active compounds through the amination of Cxe2x80x94H bonds using metal complexes as catalysts, the enantioselectivities are low, generally on the order of 20 to 30% at most.
It is a primary object of the present invention to provide a new process for the amination of Cxe2x80x94H bonds of organic compounds, particularly to provide a process by which optically active amino compounds can be produced in an enantioselective manner by the amination of the Cxe2x80x94H bonds.
After extensive studies the present inventors have now discovered that the utilization of specific salen-metal complexes as catalysts enables a highly enantioselective amination of Cxe2x80x94H bonds at allyl positions of alkenes or at benzyl positions of alkylarenes and established a new process that achieves the above-mentioned object.
Thus, according to the present invention there is provided a process for producing an amino compound from an alkene or from an alkylarene, which comprises converting the Cxe2x80x94H bond at the allyl position of the alkene or the Cxe2x80x94H bond at the benzyl position of the alkylarene, to the Cxe2x80x94N bond, wherein there are used an optically active salen-manganese complex as the catalyst and a N-substituted iminoaryliodinane as the amination agent.
In a preferred embodiment of the present invention, the optically active salen-manganese complex is one expressed by formula (1): 
In the formula (1), at least one of R1 and R2 denotes an electron-withdrawing group, and R3 denotes an alkyl group, having 1 to 4 carbon atoms or phenyl group, which may be a substituted one, or the two R3xe2x80x2s are linked together to form a five- to seven-membered alicyclic hydrocarbon group.
In a more preferred embodiment of the present invention, the electron-withdrawing group is a halogen atom, preferably bromine, and the amination agent is N-(p-toluenesulfonyl) iminophenyliodinane.